Hello, I am wondering how much computation it takes to compress audio. This information is a little hard to come by. The general situation is this: I am working on a program that will record either from the sound cards of several computers or from some card that provides several raw audio channels to be recorded from. I don't know how to estimate if I can compress all the audio in real time. How long does it usually take to compress one channel of audio (particularly, is it usually real-time)? Will real-time compression take all of the computer's resources, or could other computations be done at the same time? When the same computer needs to encode several channels of audio, could it be reasonably done in real-time? I am thinking particularly about free or open-source codecs. Do they tend to be distinctly different in performance than the patented ones? Thanks a lot, Bob.
compression speed
Started by ●April 25, 2004
Reply by ●April 25, 20042004-04-25
Reply by ●April 25, 20042004-04-25
hyperbob wrote:> Hello, > > I am wondering how much computation it takes to compress audio. This > information is a little hard to come by.What do you mean by compress? It has at least 2 very distinct meanings for audio. Regards, Dan. -- And on the evening of the first day, the lord said.... LX1, Go! And there was light. The email address *IS* valid, do not remove the spamblock.
Reply by ●April 26, 20042004-04-26
Audio or Speech?? You mentioned audio, but just wanted to make sure. The codecs are very different for the two. You are getting people confused right now :-) Regards Piyush hyperbob@walla.com (hyperbob) wrote in message news:<c0c6c733.0404250314.f23b262@posting.google.com>...> Hello, > > I am wondering how much computation it takes to compress audio. This > information is a little hard to come by. > > The general situation is this: I am working on a program that will > record either from the sound cards of several computers or from some > card that provides several raw audio channels to be recorded from. I > don't know how to estimate if I can compress all the audio in real > time. > > How long does it usually take to compress one channel of audio > (particularly, is it usually real-time)? Will real-time compression > take all of the computer's resources, or could other computations be > done at the same time? When the same computer needs to encode several > channels of audio, could it be reasonably done in real-time? > > I am thinking particularly about free or open-source codecs. Do they > tend to be distinctly different in performance than the patented ones? > > Thanks a lot, > > Bob.
Reply by ●May 2, 20042004-05-02
I was refering to speech compression (of the space-saving sort). Sorry about the confusion :-). Thanks, Bob. piyushkaul@yahoo.com (Piyush Kaul) wrote in message news:<2e20232a.0404252239.64d78ecb@posting.google.com>...> Audio or Speech?? You mentioned audio, but just wanted to make sure. > The codecs are very different for the two. You are getting people > confused right now :-) > > Regards > Piyush > > > hyperbob@walla.com (hyperbob) wrote in message news:<c0c6c733.0404250314.f23b262@posting.google.com>... > > Hello, > > > > I am wondering how much computation it takes to compress audio. This > > information is a little hard to come by. > > > > The general situation is this: I am working on a program that will > > record either from the sound cards of several computers or from some > > card that provides several raw audio channels to be recorded from. I > > don't know how to estimate if I can compress all the audio in real > > time. > > > > How long does it usually take to compress one channel of audio > > (particularly, is it usually real-time)? Will real-time compression > > take all of the computer's resources, or could other computations be > > done at the same time? When the same computer needs to encode several > > channels of audio, could it be reasonably done in real-time? > > > > I am thinking particularly about free or open-source codecs. Do they > > tend to be distinctly different in performance than the patented ones? > > > > Thanks a lot, > > > > Bob.
Reply by ●May 3, 20042004-05-03
I am assuming you are going to run this on a Pentium PC. I remember using the (encoder/decoder) of floating-point reference implementation implimentation of G.729 on PC. It would take a less than 10% cpu on 400 MHz Pentium III for a single channel. Use the floating point implementations if you can. It is faster. Other CELP based codecs like GSM-AMR/G.723.1 etc would also take processing in the same range. Hope that is the idea you were looking for. As for "how long", most such speech codecs have a frame lengths of ~10-20 ms, and the algorithmic delay may span ~10-50 ms. Regards Piyush hyperbob@walla.com (hyperbob) wrote in message news:<c0c6c733.0405020232.6083763b@posting.google.com>...> I was refering to speech compression (of the space-saving sort). Sorry > about the confusion :-). > > Thanks, > > Bob. > > piyushkaul@yahoo.com (Piyush Kaul) wrote in message news:<2e20232a.0404252239.64d78ecb@posting.google.com>... > > Audio or Speech?? You mentioned audio, but just wanted to make sure. > > The codecs are very different for the two. You are getting people > > confused right now :-) > > > > Regards > > Piyush > > > > > > hyperbob@walla.com (hyperbob) wrote in message news:<c0c6c733.0404250314.f23b262@posting.google.com>... > > > Hello, > > > > > > I am wondering how much computation it takes to compress audio. This > > > information is a little hard to come by. > > > > > > The general situation is this: I am working on a program that will > > > record either from the sound cards of several computers or from some > > > card that provides several raw audio channels to be recorded from. I > > > don't know how to estimate if I can compress all the audio in real > > > time. > > > > > > How long does it usually take to compress one channel of audio > > > (particularly, is it usually real-time)? Will real-time compression > > > take all of the computer's resources, or could other computations be > > > done at the same time? When the same computer needs to encode several > > > channels of audio, could it be reasonably done in real-time? > > > > > > I am thinking particularly about free or open-source codecs. Do they > > > tend to be distinctly different in performance than the patented ones? > > > > > > Thanks a lot, > > > > > > Bob.